Timing insecticide applications for managing European corn borer (Lepidoptera: Pyralidae) infestations in potato

European corn borer, Ostrinia nubilalis (Hubner), management using insecticides was investigated in Irish potato, Solanum tuberosum L, in eastern North Carolina. Additionally, activity of corn borer larvae on untreated 'Kennebec' potato plants was evaluated. Corn borer larvae produced new tunnels at the same rate throughout their development and ultimately produced 4.7 +/- 0.4 (mean +/- SEM) tunnels per plant per larva. Thus, for any given corn borer infestation level, estimates of damage to the crop will increase as the season progresses. Application timing of carbofuran, methamidophos and esfenvalerate were evaluated for control of corn borer damage in 'Atlantic' potato. The type and rate of insecticide and the level of corn borer damage at the time of application affected the level of damage at the end of the season. The greatest reduction in damage occurred when the insecticide was applied when many neonates were observed penetrating the plant. A single application of either carbofuran (1.12 kg a.i. ha(-1)) or methamidophos (0.84 or 1.12 kg a.i. ha(-1)) when approximate to 20-40% of the stems are damaged in early May should improve European corn borer management in potato. Copyright (C) 1995 Elsevier Science Ltd.